Field of the Invention
The present invention relates to a method for the generative production of components, particularly for the production of components of turbomachines in which the component is constructed in layers on a substrate or on a previously produced part of the component, with construction in layers occurring by melting powder material in layers with a high-energy beam and solidification of the melt.
Prior Art
Generative production methods for producing a component, such as, for example, stereolithographic methods, selective laser melting, selective laser sintering, electron beam melting, or laser deposition welding, are used in the industry for so-called rapid tooling and rapid prototyping or also for the mass production of products within the scope of rapid manufacturing. In particular, such methods can also be used for the production of turbine parts, particularly parts for aircraft engines, in which such generative production methods are advantageous on account of the material used, for example. An example of this is found in DE 10 2010 050 531 A1.
Moreover, owing to the conditions of use and the requisite properties, it is advantageous in the case of components for turbomachines to use single-crystalline or directionally solidified components in order to specifically exploit the anisotropy of properties, such as, for example, different mechanical properties with respect to crystal orientation. Thus, for example, it is known how to produce turbine blades or vanes from single-crystalline or directionally solidified nickel-based superalloys. Here, single crystalline means that the component is formed from a single crystal, so that there are no grain boundaries. Although many crystal grains are present in the component in the case of directionally solidified components, the latter are nearly identical with respect to their crystal orientation and, in particular, they are oriented in a preferred direction so as to exploit the special properties along the preferred direction.
Because the production of such components is very complicated, an attempt has already been made to produce such components by generative methods as well and this can be advantageous in the case of small-scale serial production, for example. Examples of this are described in EP 0 861 927 A1, EP 0 892 090 A1, WO 2004/028786 A1, WO 2013/029959 A1, or DE 10 2009 051 479 A1.
However, there continues to be a need for improving the known methods in order to improve the quality of the single-crystalline or directionally solidified components produced and to be able to use the method reproducibly on an industrial scale. In particular, a method that enables the targeted control of the construction in layers is needed in order to be able to adjust the anisotropy properties of the produced component in a defined manner.